1. Edit product is not working : Please check your permalinks settings. You have to navigate to Settings->Permalinks and set permalinks as “post name” and “product”. Now check and let me know.

2.Undefined error on dashboard setting : Please open wp-content/plugins/wedevs-dokan-plugin/classes/template-settings.php. In line number 99 you will see something like this 'address' => strp_tags( $_POST['setting_address'] ),. You have to write this line as 'address' => strip_tags( $_POST['setting_address'] ),. Hope this problem will be solved

In your second post

There is one more issue on the site http://keysartisans.com/dev, if user is not login then featured products aren’t coming and only coming when you are login.

Can you please describe me in more details?. If you can then provide some screenshot here to make me more clear.